Tree Pests Burrowing to the Roots

Borers and other pests can attack tree roots and damage them.

While bugs, such as sucking pests and chewing pests, feed primarily on foliage and other tender plant growth, some pests bore deeper into trees and may burrow all the way down into roots. While borers are not all identical, what they do have in common is the significant threat they pose to the health of trees. Keep up on tree maintenance and care to help prevent borer pests. Monitor trees regularly and use control methods, because borer damage can kill trees.

Types

The term "borer" refers to pests that tunnel into plants. Different species and types of borer pests infest different types of trees. Become familiar with the types of borers that commonly infest your trees so you know what to look for. Borer adults often appear as wasplike, clear-winged or solid-winged moths, beetles, long-horned beetles and hard-bodied bugs, called weevils, that often have elongated snouts. Most larvae look like grubs or caterpillars, generally with cream-colored bodies.

Activity

Adult borers typically deposit eggs on or beneath tree bark, in wounds or on protected areas, such as bends on tree limbs. Many borers lay eggs on exposed roots or the base of tree trunks. Most borers choose weakened trees and newly fallen limbs, notes the University of Nebraska-Lincoln Extension. So, expect greater activity on damaged or stressed plants. Once the eggs hatch, larvae bore into the tree, often feeding beneath bark and then tunneling deeper, where they develop. In the case of root and base borers, such as redheaded ash borers (Neoclytus acuminatus), the larvae tunnel into roots where they feed. Look for frass, or the sawdust-like remnants of bark and wood, which is left as a result of tunneling.

Effects

While minor infestations may result in little apparent damage, severe infestations may be more destructive. Though borers that feed above the ground often cause visible tunneling in wood, root-feeding borers feed with few visible above-ground symptoms. Look for entry holes near the base of the tree or on exposed roots. Trees may have an overall ragged appearance, peeling bark and dead areas where borers have girdled plant parts. Because the root system provides water and nutrients to the tree, once it is heavily infested, the affected tree will decline and die.

Control

Most borer problems can be prevented by maintaining vigorous, healthy trees. Pay close attention to proper care, such as correct sun exposure, watering, fertilization and pruning. Removal of weakened or injured plant parts as well as plant debris, felled trees or logs decreases susceptible feeding sites for borers. Avoid accidental injuries to trees when you're working near them with tools to protect them from wounds that diminish health and act as entry points for borers. Applying insecticides with active ingredients, such as carbaryl, may kill eggs. The most effective insecticides are only available to licensed professionals, notes University of California Integrated Pest Management Online, but there are no effective chemical treatments for existing infestations.

About the Author

Tarah Damask's writing career began in 2003 and includes experience as a fashion writer/editor for Neiman Marcus, short fiction publications in "North Texas Review," a self-published novel, band biographies, charter school curriculum and articles for various websites. Damask holds a Master of Arts in English and creative writing from the University of North Texas.